05000361/FIN-2013003-02
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Finding | |
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| Title | Procedure Adequacy for Responding to External Flooding Events |
| Description | The inspectors identified an unresolved item for a potentially inadequate procedure for response to external flooding events and potential failure to follow procedures to complete an appropriate evaluation for inaccessible flood protection features. The inspectors reviewed alarm response Procedure SO23-15-57.C, Alarm Response Instruction, Revision 28, which included a guide for identifying which flood sensor area was transmitting the alarm to the control room. The procedure included step 1.0, Required Actions, step 2.0, Corrective Actions, step 3.0, Associated Responses, and step 4.0, Compensatory Actions. Step 1.0 included immediately dispatching an operator to ensure doors and manholes in the area were closed. Step 2.0 listed specific causes that may be the source of internal flooding from specific components (tanks, pumps, valves, etc.). Step 3.0 included steps to isolate or secure the component identified as the cause of the internal flooding, as well as initiation of Procedure SO23-2-16, Operating Instruction, Revision 36, for removing water by use of temporary sump pumps for some of the spaces, where other spaces relied on internal sumps. The procedure did not provide details on manpower, equipment locations, equipment maintenance, disposal of flood waters, nor analysis supporting how quickly the water would need to be removed to prevent affecting safety-related equipment or spaces for conditions associated with an external flooding event. As part of this inspection, the inspectors reviewed Calculation M-0120-015, Plant Flood Analysis, which included an assessment of the worst case internal flooding event in spaces, and compared it to external flooding scenarios. Additionally, the inspectors observed that Procedure SO-23-XV-94, step 6.6.2.1.1, required that, if more than one inaccessible flood protection feature with potential loss of function is reported, then an evaluation of the aggregate effect on flood protection features must be provided. The licensee did not evaluate a possible common cause failure of these features and its cumulative effect on flooding protection features on site, as required in NEI 12-07, Section 5.1, which stated in part that, if more than one inaccessible flood protection feature with potential loss of function is reported, then an evaluation of the aggregate effect flood protection features must be provided. The licensee documented these issues in the corrective action program as Nuclear Notifications NN202370058 and NN202157052. The inspectors had a number of questions and concerns regarding assumptions and conclusions from the flooding analysis that were not resolved at the end of the inspection period. Additional inspection is necessary to complete the review and determine whether procedures were inadequate for response to external flooding events and whether an evaluation for certain inaccessible flood protection features was appropriate and necessary. As a result, the inspectors identified Unresolved Item URI 05000361;362/2013003-02, Procedure Adequacy for Responding to External Flooding Events. |
| Site: | San Onofre  |
|---|---|
| Report | IR 05000361/2013003 Section 4OA5 |
| Date counted | Jun 30, 2013 (2013Q2) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | |
| Inspectors (proximate) | A Howell R Evansn Taylorr Lantz J Reynoso J Laughlin G Warnick M Williams C Hale |
| INPO aspect | |
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Finding - San Onofre - IR 05000361/2013003 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (San Onofre) @ 2013Q2
Self-Identified List (San Onofre)
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